Prevalence of Entamoeba histolytica/Entamoeba dispar in the city of Campina Grande, in northeastern Brazil.

There is a clear need to perform epidemiological studies to find the true prevalence of Entamoeba histolytica around the world. The evaluation of this prevalence has been hindered by the existence of two different species which are morphologically identical, but genetically different, namely E. histolytica, which causes amebiasis, and E. dispar, which is non-pathogenic. In Brazil, the E. dispar has been detected in communities in the Southeastern (SE) and Northeastern (NE) regions with poor sanitation. However, individuals infected with E. histolytica have been identified in other regions. There is an absence of reports on the prevalence of these parasites in the state of Paraíba, which also has areas with poor sanitary conditions where a high prevalence of the E. histolytica/E. dispar complex has been detected in children from urban slums. The present study evaluated the prevalence of E. histolytica and E. dispar in 1,195 asymptomatic children between two and 10 years of age, living in a sprawling urban slum in Campina Grande, in the state of Paraíba, in Northeastern Brazil. These children were examined and their feces samples were analyzed microscopically. A total of 553 children tested positive for the E. histolytica/E. dispar complex, and 456 of the positive samples were tested with the E. histolytica II® ELISA kit. All 456 samples were negative for the presence of the adhesin E. histolytica specific antigen. The evidence suggests that in this community E. histolytica is absent and E. dispar is the dominant species.

PREVALENCE OF Entamoeba histolytica/Entamoeba dispar IN THE CITY OF CAMPINA GRANDE, IN NORTHEASTERN BRAZIL / Prevalência de Entamoeba histolytica/Entamoeba dispar na cidade de Campina Grande, Nordeste do Brasil

There is a clear need to perform epidemiological studies to find the true prevalence of Entamoeba histolytica around the world. The evaluation of this prevalence has been hindered by the existence of two different species which are morphologically identical, but genetically different, namely E. histolytica, which causes amebiasis, and E. dispar, which is non-pathogenic. In Brazil, the E. dispar has been detected in communities in the Southeastern (SE) and Northeastern (NE) regions with poor sanitation. However, individuals infected with E. histolytica have been identified in other regions. There is an absence of reports on the prevalence of these parasites in the state of Paraíba, which also has areas with poor sanitary conditions where a high prevalence of the E. histolytica/E. dispar complex has been detected in children from urban slums. The present study evaluated the prevalence of E. histolytica and E. dispar in 1,195 asymptomatic children between two and 10 years of age, living in a sprawling urban slum in Campina Grande, in the state of Paraíba, in Northeastern Brazil. These children were examined and their feces samples were analyzed microscopically. A total of 553 children tested positive for the E. histolytica/E. dispar complex, and 456 of the positive samples were tested with the E. histolytica II® ELISA kit. All 456 samples were negative for the presence of the adhesin E. histolytica specific antigen. The evidence suggests that in this community E. histolytica is absent and E. dispar is the dominant species.

A prevalência mundial de Entamoeba histolytica não está bem estabelecida. Este fato deve-se à complicação derivada da existência de duas espécies morfologicamente idênticas, mas geneticamente diferentes: a E. histolytica que causa amebíases e a E. dispar descrita como não patogênica. No Brasil, em comunidades com precárias condições sanitárias e endêmicas para várias parasitoses, localizadas nas regiões Sudeste (SE) e Nordeste (NE), somente E. dispar tem sido encontrada, porém outras regiões, apresentam indivíduos infectados por E. histolytica. Na região agreste do Estado da Paraíba (NE) que apresenta as mesmas precárias condições sanitárias, não tem sido reportada prevalência específica destes parasitos, embora fosse encontrada alta prevalência do complexo E. dispar/E. histolytica em crianças em favela urbana. O presente estudo foi realizado em favela da cidade de Campina Grande, Estado da Paraíba, onde 1.195 crianças de dois a 10 anos sem sintomatologia foram examinadas. Amostras de fezes destas crianças foram analisadas microscopicamente, encontrando-se 553 positivas para o complexo E. dispar/E. histolytica. Do total de amostras positivas, 456 foram submetidas à pesquisa do antígeno especifico para E. histolytica pelo teste ELISA E. histolytica II®,obtendose resultado negativo para a presença do antígeno adesina específico de E. histolytica, em todas as amostras testadas. Os resultados sugerem que nesta comunidade não há infecção por E. histolytica, e que E. dispar é a espécie dominante na região.

Severity of atopic dermatitis and Ascaris lumbricoides infection: an evaluation of CCR4+ and CXCR3+ helper T cell frequency / Gravidade da dermatite atópica e infecção por Ascaris lumbricoides: uma avaliação da frequência de células T auxiliares CCR4+ e CXCR3+

INTRODUCTION: Ascaris lumbricoides-infected patients present lower prevalence of severe atopic dermatitis. METHODS: Peripheral blood of infected children with atopic dermatitis was assessed by flow cytometry of the frequency of Th1 and Th2 cells through the expression of CXCR3 and CCR4 chemokine receptors, respectively. RESULTS: Helminth-free patients with atopic dermatitis presented a high frequency of CCR4+Th2 cells. Parasitized patients with atopic dermatitis showed a lower frequency of CXCR3+Th1 cells compared to infected individuals only. CONCLUSIONS: Ascariasis modifies the blood traffic of Th2 cells in atopic dermatitis patients, while the allergic disease down-regulates the traffic of Th1 cells in parasitized patients.

INTRODUÇÃO: Pacientes infectados com Ascaris lumbricoides apresentam menor prevalência de dermatite atópica grave. MÉTODOS: Sangue periférico de crianças infectadas com dermatite atópica foi analisado por citometria de fluxo quanto à frequência de células Th1 e Th2 pela expressão de receptores de quimiocina CXCR3 e CCR4, respectivamente. RESULTADOS: Pacientes sem helmintos com dermatite atópica apresentaram alta frequência de células Th2CCR4+. Pacientes parasitados com dermatite atópica apresentaram menor frequência de células Th1CXCR3+ comparados aos indivíduos apenas infectados. CONCLUSÕES: Ascaridiases altera o tráfego sanguíneo de células Th2 em pacientes com dermatite atópica, enquanto a doença alérgica diminui o tráfego de células Th1 em pacientes parasitados.

Immunohistopathological changes in murine Schistosomiasis mansoni under the influence of N-acetyl-L-cysteine.

The main pathology associated with Schistosomiasis mansoni is granulomatous inflammation that may develop into hepatosplenic disease with fibrosis and hepatoesplenomegaly. It is known that N-acetyl-L-cysteine (NAC) reduces tissue damage in chronic liver diseases owing to its anti-inflammatory, antioxidant, and detoxifying properties. In this study, we investigated the imunohistopathological changes in murine schistosomiasis mansoni under the influence of NAC, in combination with Praziquantel (PZQ) or not. Three groups of mice were formed to evaluate the effects of NAC during infection in the acute, intermediate, and chronic phases. Each group was further subdivided into four subgroups: NAC, PZQ, NAC + PZQ and control (without treatment). Oral administration of NAC (200 mg/kg/day) was carried out on the first day after infection for the acute phase and on the 45th for the intermediate and chronic phases for 59 and 45, 75 days, respectively. PZQ (100 mg/kg/day), was given orally by gavage from the 45th to 49th day after infection. Histopathological analysis of liver tissue provided evidence that combined NAC + PZQ treatment reduced the development of granulomas observed in the chronic phase. Animals treated with NAC and/or PZQ showed a reduction in the size of granulomas and all those treated with NAC exhibited a lower degree of fibrosis. In all groups, NAC decreased the synthesis of interferon-γ and nitric oxide, while increasing the levels of interleukin-10, but it did not influence the production of interleukin-4. On the whole, NAC treatment induced an immunomodulatory effect and reduced liver damage during the granulomatous inflammation in S. mansoni-infected mice.

Severity of atopic dermatitis and Ascaris lumbricoides infection: an evaluation of CCR4+ and CXCR3+ helper T cell frequency.

INTRODUCTION: Ascaris lumbricoides-infected patients present lower prevalence of severe atopic dermatitis. METHODS: Peripheral blood of infected children with atopic dermatitis was assessed by flow cytometry of the frequency of Th1 and Th2 cells through the expression of CXCR3 and CCR4 chemokine receptors, respectively. RESULTS: Helminth-free patients with atopic dermatitis presented a high frequency of CCR4+Th2 cells. Parasitized patients with atopic dermatitis showed a lower frequency of CXCR3+Th1 cells compared to infected individuals only. CONCLUSIONS: Ascariasis modifies the blood traffic of Th2 cells in atopic dermatitis patients, while the allergic disease down-regulates the traffic of Th1 cells in parasitized patients.

Ocular toxoplasmosis: evaluation of lacrimal-specific secretory IgA levels in both patients with active and inactive phases of the disease.

Ocular toxoplasmosis can result in recurrent uveitis. Studies have shown that a correlation between active ocular toxoplasmosis and the presence of anti-Toxoplasma gondii secretory IgA (SIgA) in tears. This study compares anti-T. gondii SIgA levels in patients' tears during the acute and inactive phases of toxoplasmic uveitis. Twenty-nine positive tear specific SIgA for T. gondii patients with acute toxoplasmic uveitis were selected and were followed-up for at least two years, when the anti-T. gondii SIgA tears levels were determined. Specific SIgA for T. gondii was negative in 22 patients (75.86%) and positive in seven patients (24.13%) of whom six (85.7%) were followed over three years. Average SIgA levels during the acute phase are 1.54 and decrease significantly to 0.72 (p = 0.0001) during the inactive phase of disease. Because anti-T. gondii SIgA in the tear is negative in 75.86% of patients after the acute phase of infection, T. gondii SIgA levels may be used as a complementary diagnostic marker for active ocular toxoplasmosis.

Ocular toxoplasmosis: evaluation of lacrimal - specific secretory IgA levels in both patients with active and inactive phases of the disease

Ocular toxoplasmosis can result in recurrent uveitis. Studies have shown that a correlation between active ocular toxoplasmosis and the presence of anti-Toxoplasma gondii secretory IgA (SIgA) in tears. This study compares anti-T. gondii SIgA levels in patients' tears during the acute and inactive phases of toxoplasmic uveitis. Twenty-nine positive tear specific SIgA for T. gondii patients with acute toxoplasmic uveitis were selected and were followed-up for at least two years, when the anti-T. gondii SIgA tears levels were determined. Specific SIgA for T. gondii was negative in 22 patients (75.86 percent) and positive in seven patients (24.13 percent) of whom six (85.7 percent) were followed over three years. Average SIgA levels during the acute phase are 1.54 and decrease significantly to 0.72 (p = 0.0001) during the inactive phase of disease. Because anti-T. gondii SIgA in the tear is negative in 75.86 percent of patients after the acute phase of infection, T. gondii SIgA levels may be used as a complementary diagnostic marker for active ocular toxoplasmosis.

Influence of maternal schistosomiasis on the immunity of adult offspring mice.

Schistosoma mansoni infection modulates the immunity to unrelated antigens in the host. In this study, we have investigated the effect of pregnancy and nursing from schistosomotic mother mice on the immune response to ovalbumin (OA), in adult offspring. Then, newborn mice were divided into four groups: animals born from infected mothers (BIM) suckled by non-infected mothers; animals from non-infected mothers suckled by infected mothers (SIM); and two other groups that were mice born and suckled in infected mothers (BSIM) or non-infected (control) mothers. The adult offspring were immunized with OA plus adjuvant. We compared the OA-specific hypersensitivity reactions (HR), antibodies levels (IgG, IgG2a) and the cytokine production in splenocyte cultures. Remarkable interleukin (IL)-10 synthesis was observed in mice BIM; while the anti-OA antibodies levels and immediate HR were impaired. IL-10 neutralization recovered this suppression. Differently, in mice SIM and BSIM there was an enhancement in the anti-OA humoral response and high IL-2 production, however low level of the IL-10 was detected in mice BSIM. In conclusion, schistosomotic pregnancy provides an immunosuppressive potential, IL-10 dependent, which was sustained throughout adult life. Regardless, suckling by infected mothers induces great responsiveness to an unrelated antigen and repairs the inhibitory potential acquired during prenatal stage.

Atopic dermatitis and ascariasis in children aged 2 to 10 years.

OBJECTIVE: To assess the association between atopic dermatitis (AD) and ascariasis in 2 to 10-aged children from the neighborhood Pedregal, in the city of Campina Grande, Brazil, an area of low socioeconomic index. METHODS: Cross-sectional study conducted with the use of the standard questionnaire from the International Study of Asthma and Allergies in Childhood (ISAAC) and stool parasitological exam for Ascaris lumbricoides. The dependent variable was AD diagnosis: absent, mild, and severe. Multivariate logistic regression and descriptive analysis of the variable were used. Associations were estimated using relative risk (RR) and odds ratio (OR). The statistical inference was based on 95% confidence intervals (95%CI). RESULTS: We assessed 1,195 children, 612 (51.2%) female. The AD prevalence was 24.6%, and ascariasis prevalence was 26.1%. In the mild AD group of children, 44 (36.7%) were infected by A. lumbricoides while in the severe AD group, 40 (22.9%) had the same geohelminthosis (p = 0.01). Comparing negative cases of AD between mild and severe forms, the infection with A. lumbricoides increased the frequency of mild AD (RR = 1.7; p = 0.009), but not the severe form (RR = 0.86; p = 0.46). Evaluating only the positive cases of dermatitis, 120 mild AD (40.8%) and 176 with severe AD (58.2%), it can be said that the exposure to the parasite decreased the frequency of the severe form of dermatitis (RR = 1.46; p = 0.016). CONCLUSION: There is a high prevalence of AD and of ascariasis in the population studied. The severe AD is related to lower parasitemia of A. lumbricoides.

Dermatite atópica e ascaridíase em crianças de 2 a 10 anos / Atopic dermatitis and ascariasis in children aged 2 to 10 years

Objetivo: Avaliar a associação entre dermatite atópica (DA) e ascaridíase em crianças de 2 a 10 anos do bairro do Pedregal, Campina Grande (PB), área de baixos indicadores socioeconômicos. Métodos: Trata-se de estudo transversal a partir da aplicação do questionário padrão do International Study of Asthma and Allergies in Chlidhood (ISAAC) e exame parasitológico de fezes para Ascaris lumbricoides. A variável dependente foi o diagnóstico de DA ausente, DA leve e DA grave. Efetuou-se análise de regressão logística multivariada, bem como análise descritiva das variáveis do estudo. As associações foram estimadas por meio de risco relativo (RR) e razão de chances (odds ratio, OR). A inferência estatística foi baseada em intervalos de confiança de 95 por cento (IC95 por cento). Resultados: Foram avaliadas 1.195 crianças, sendo 51,2 por cento (n = 612) do sexo feminino. A prevalência de DA foi de 24,6 por cento, e a de ascaridíase, de 26,1 por cento. Das crianças com DA leve, 44 (36,7 por cento) eram parasitadas pelo A. lumbricoides, enquanto que 40 (22,9 por cento), com DA grave, apresentavam a mesma geo-helmintose (p = 0,01). Comparando-se os casos negativos para DA com os casos leves e graves, constatou-se que a presença de ascaridíase aumentou a ocorrência de dermatite leve (RR = 1,7; p = 0,009), mas não de DA grave (RR = 0,86; p = 0,46). Avaliando-se apenas os casos positivos de dermatite, DA leve (n = 120; 40,8 por cento) e DA grave (n = 176; 59,2 por cento), verifica-se que a exposição parasitária diminui a ocorrência da forma grave (RR = 1,46; p = 0,016). Conclusão: Existe elevada prevalência de DA e de ascaridíase na população estudada. A forma grave de DA está associada com baixa parasitemia de A. lumbricoides.

Objective: To assess the association between atopic dermatitis (AD) and ascariasis in 2 to 10-aged children from the neighborhood Pedregal, in the city of Campina Grande, Brazil, an area of low socioeconomic index. Methods:Cross-sectional study conducted with the use of the standard questionnaire from the International Study of Asthma and Allergies in Childhood (ISAAC) and stool parasitological exam for Ascaris lumbricoides. The dependent variable was AD diagnosis: absent, mild, and severe. Multivariate logistic regression and descriptive analysis of the variable were used. Associations were estimated using relative risk (RR) and odds ratio (OR). The statistical inference was based on 95 percent confidence intervals (95 percentCI). Results: We assessed 1,195 children, 612 (51.2 percent) female. The AD prevalence was 24.6 percent, and ascariasis prevalence was 26.1 percent. In the mild AD group of children, 44 (36.7 percent) were infected by A. lumbricoides, while in the severe AD group, 40 (22.9 percent) had the same geohelminthosis (p = 0.01). Comparing negative cases of AD between mild and severe forms, the infection with A. lumbricoides increased the frequency of mild AD (RR = 1.7; p = 0.009), but not the severe form (RR = 0.86; p = 0.46). Evaluating only the positive cases of dermatitis, 120 mild AD (40.8 percent) and 176 with severe AD (58.2 percent), it can be said that the exposure to the parasite decreased the frequency of the severe form of dermatitis (RR = 1.46; p = 0.016). Conclusion: There is a high prevalence of AD and of ascariasis in the population studied. The severe AD is related to lower parasitemia of A. lumbricoides.

Anti-Toxoplasma gondii secretory IgA in tears of patients with ocular toxoplasmosis: immunodiagnostic validation by ELISA.

Toxoplasma gondii causes posterior uveitis and the specific diagnosis is based on clinical criteria. The presence of anti-T. gondii secretory IgA (sIgA) antibodies in patients' tears has been reported and an association was found between ocular toxoplasmosis and the anti-T. gondii sIgA isotype in Brazilian patients. The purpose of this study was to provide an objective validation of the published ELISA test for determining the presence of anti-T. gondii sIgA in the tears of individuals with ocular toxoplasmosis. Tears from 156 patients with active posterior uveitis were analysed; 82 of them presented characteristics of ocular toxoplasmosis (standard lesion) and 74 patients presented uveitis due to other aetiologies. Cases of active posterior uveitis were considered standard when a new inflammatory focus satellite to old retinochoroidal scars was observed. The determination of anti-T. gondii sIgA was made using an ELISA test with crude tachyzoite antigenic extracts. Tears were collected without previous stimulation. Detection of sIgA showed 65.9% sensitivity (95% CI = 54.5-74.4), 71.6% specificity (95% CI = 59.8-81.2), a positive predictive value of 72% (95% CI = 60.3-81.5) and a negative predictive value of 65.4% (95% CI = 54.0-75.4). sIgA reactivity was higher in the tears of patients with active posterior uveitis due to T. gondii (p < 0.05). The test is useful for differentiating active posterior uveitis due to toxoplasmosis from uveitis caused by other diseases.

Anti-Toxoplasma gondii secretory IgA in tears of patients with ocular toxoplasmosis: immunodiagnostic validation by ELISA

Toxoplasma gondii causes posterior uveitis and the specific diagnosis is based on clinical criteria. The presence of anti-T. gondii secretory IgA (sIgA) antibodies in patients' tears has been reported and an association was found between ocular toxoplasmosis and the anti-T. gondii sIgA isotype in Brazilian patients. The purpose of this study was to provide an objective validation of the published ELISA test for determining the presence of anti-T. gondii sIgA in the tears of individuals with ocular toxoplasmosis. Tears from 156 patients with active posterior uveitis were analysed; 82 of them presented characteristics of ocular toxoplasmosis (standard lesion) and 74 patients presented uveitis due to other aetiologies. Cases of active posterior uveitis were considered standard when a new inflammatory focus satellite to old retinochoroidal scars was observed. The determination of anti-T. gondii sIgA was made using an ELISA test with crude tachyzoite antigenic extracts. Tears were collected without previous stimulation. Detection of sIgA showed 65.9 percent sensitivity (95 percent CI = 54.5-74.4), 71.6 percent specificity (95 percent CI = 59.8-81.2), a positive predictive value of 72 percent (95 percent CI = 60.3-81.5) and a negative predictive value of 65.4 percent (95 percent CI = 54.0-75.4). sIgA reactivity was higher in the tears of patients with active posterior uveitis due to T. gondii (p < 0.05). The test is useful for differentiating active posterior uveitis due to toxoplasmosis from uveitis caused by other diseases.

[Clinical characteristics of 64 individuals carrying active posterior presumptively toxoplasmic uveitis, in Pernambuco]. / Características clínicas de 64 indivíduos portadores de uveítis posterior activa presumiblemente toxoplásmica en Pernambuco.

PURPOSE: To describe clinical characteristics of posterior active uveitis presumptively by Toxoplasma gondii (PAUPT) in patients with typical lesion. Tranversal study. METHODS: Sixty-four patients with retinochoroiditis scatter and active satellite lesions examined in Pernambuco, Brazil. All were older than 10 years and immunocompetent. Gender, age, skin color, and residence were recorded. Previous uveitis, visual accuracy, intraocular pressure (IOP), and ocular examination were analyzed. RESULTS: 52% were males, most of them with white skin (68.8%). Mean age 29 years (+/-10.87). Eighty-four percent of the patients lived in the metropolitan area. 56.2% were having the first episode of uveitis. In the damaged eye, visual accuracy mean was 20/200, IOP mean 14.5 mmHg (+/-64). Hyperemia of the conjunctiva was observed in 29.7% of the patients and alterations of the cornea in 51.6%. There were cells in the aqueous humor in 62.7%. 6.2% had posterior synechiae. All had vitreous damage and 45.3% retinal vasculitis. In 42.2% of the patients, lesions were located in zone I of Holland and 90.6% had the size of one discus diameter or greater. Neuritis was observed in 28.2%. Uveitis was more frequent in the right eye (54.7%). CONCLUSION: PAUPT affects young people and the main symptom was reduction of visual acuity. IOP mean was normal. Alterations of the vitreous were observed in all cases. Injuries were equal to one discus diameter or greater and located in zone I of Holland.

Características clínicas de 64 indivíduos portadores de uveítis posterior activa presumiblemente toxoplásmica en Pernambuco / Clinical characteristics of 64 individuals carrying active posterior presumptively toxoplasmic uveitis, in Pernambuco

OBJETIVO: Describir características clínicas de uveítis posterior activa, presumiblemente por Toxoplasma gondii (UPAPT) en portadores de lesión típica. Estudio tranversal. MÉTODOS: 64 portadores de UPAPT con retinocorroiditis cicatrizada y lesión satélite activa, mayores de 10 años, inmunocompetentes, examinados en Permambuco, Brazil. Se analizó: sexo, edad, color de la piel, procedencia, uveítis anteriores, agudeza visual, presión ocular y exámen ocular. RESULTADOS: Masculino en 52 por ciento. Edad media 29 años (±10,87). Piel blanca en 68,8 por ciento. Domicilio en la área metropolitana en 80,4 por ciento. Primer episodio de uveítis en 56,2 por ciento. Media de visión en ojo afectado 20/200. Presión ocular media 14,5 mmHg (±7,64) en ojo afectado. Conjuntiva hiperemiada en 29,7 por ciento. Alteraciones corneales en 51,6 por ciento. Células en el humor acuoso en 67,2 por ciento. Sinéquias posteriores en 6,2 por ciento. Compromiso vítreo en 100 por ciento. Vasculitis retiniana en 45,3 por ciento. Lesiones localizads en la zona I de Holland en 42,2 por ciento, siendo de tamaño igual o mayor de un diámetro de disco en 90,6 por ciento. Neuritis en 28,2 por ciento. CONCLUSIÓN: UPAPT afecta adultos jóvenes, siendo el síntoma principal la disminución de la visión. Presión ocular media normal. Compromiso vítreo en todos los casos. Com mayor frequencia las lesiones fueron mayores de un diámetro de disco localizadas en la zona I de Holland.

PURPOSE: To describe clinical characteristics of posterior active uveitis presumptively by Toxoplasma gondii (PAUPT) in patients with typical lesion. Tranversal study. METHODS: Sixty-four patients with retinochoroiditis scatter and active satellite lesions examined in Pernambuco, Brazil. All were older than 10 years and immunocompetent. Gender, age, skin color, and residence were recorded. Previous uveitis, visual accuracy, intraocular pressure (IOP), and ocular examination were analyzed. RESULTS: 52 percent were males, most of them with white skin (68.8 percent). Mean age 29 years (±10.87). Eighty-four percent of the patients lived in the metropolitan area. 56.2 percent were having the first episode of uveitis. In the damaged eye, visual accuracy mean was 20/200, IOP mean 14.5 mmHg (±64). Hyperemia of the conjunctiva was observed in 29.7 percent of the patients and alterations of the cornea in 51.6 percent. There were cells in the aqueous humor in 62.7 percent. 6.2 percent had posterior synechiae. All had vitreous damage and 45.3 percent retinal vasculitis. In 42.2 percent of the patients, lesions were located in zone I of Holland and 90.6 percent had the size of one discus diameter or greater. Neuritis was observed in 28.2 percent. Uveitis was more frequent in the right eye (54.7 percent). CONCLUSION: PAUPT affects young people and the main symptom was reduction of visual acuity. IOP mean was normal. Alterations of the vitreous were observed in all cases. Injuries were equal to one discus diameter or greater and located in zone I of Holland.

New imidazolidinic bioisosters: potential candidates for antischistosomal drugs

The emergence of strains of Schistosoma resistant to praziquantel has drawn attention to the search for new schistosomacide drugs. Imidazolidinic derivatives have performed outstandingly against adult S. mansoni worms when evaluated in vitro. The molecular modification of imidazolidine by way of bioisosteric replacement gives rise to variations in its biological response. This study verifies the potential of substituent groups in the derivatives (Z)3-benzyl-5-(2-fluoro-benzylidene)-imidazolidine-2,4-dione NE4, 3-benzyl-5-(4-chloro-arylazo)-4-thioxo-imidazolidin -2-ona PT5, 3-benzyl-5-(3-fluoro-benzylidene)-1-methyl-2-thioxo-imidazolidin-4-one JT53; 3-benzyl-1-methyl-5-(4-methyl-benzylidene)-2-thioxo-imidazolidin-4-one JT63; 3-benzyl-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo -imidazolidin-4-one JT68; 3-(4-chloro-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT69; 3-(4-phenyl-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT72 by determining the viability in vitro of adult S. mansoni worms in the presence of these derivatives. The susceptibility of the worms obtained from mice and kept in culture in the presence of different concentrations was determined by way of schistosomacide kinetic, observed every 24 h over a period of eight days. The results show that the worms were more sensitive to the PT5 derivative at a concentration of 58 æM which killed 100 percent of the worms after 24 h of contact, also giving rise to alterations in the tegument surface of the worms with the formation of bubbles and peeling. These observations suggest a strong electronic contribution of the arylazo grouping in the biological response.

Preliminary results on interleukin-4 and interleukin-10 cytokine production in malnourished, inducible nitric oxide synthase-deficient mice with schistosomiasis mansoni infection

Schistosoma mansoni infected C57Bl/6 inducible nitric oxide synthase (iNOS)-deficient and non-deficient malnourished mice, both fed a balanced controlled diet were studied. Interleukins, IL-4 and IL-10 responses to soluble egg antigens (SEA) 90 days after infection, were determined. Our results suggest that in iNOS deficient, malnourished mice, 90 days after of infection, nitric oxide has a downregulating effect on IL-4 and IL-10 production. We are currently investigating the biological significance of these findings.

New imidazolidinic bioisosters: potential candidates for antischistosomal drugs.

The emergence of strains of Schistosoma resistant to praziquantel has drawn attention to the search for new schistosomacide drugs. Imidazolidinic derivatives have performed outstandingly against adult S. mansoni worms when evaluated in vitro. The molecular modification of imidazolidine by way of bioisosteric replacement gives rise to variations in its biological response. This study verifies the potential of substituent groups in the derivatives (Z)3-benzyl-5-(2-fluoro-benzylidene)-imidazolidine-2,4-dione NE4, 3-benzyl-5-(4-chloro-arylazo)-4-thioxo-imidazolidin -2-ona PT5, 3-benzyl-5-(3-fluoro-benzylidene)-1-methyl-2-thioxo-imidazolidin-4-one JT53; 3-benzyl-1-methyl-5-(4-methyl-benzylidene)-2-thioxo-imidazolidin-4-one JT63; 3-benzyl-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo -imidazolidin-4-one JT68; 3-(4-chloro-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT69; 3-(4-phenyl-benzyl)-1-methyl-5-(4-methoxi-benzylidene)-2-thioxo-imidazolidin-4-one JT72 by determining the viability in vitro of adult S. mansoni worms in the presence of these derivatives. The susceptibility of the worms obtained from mice and kept in culture in the presence of different concentrations was determined by way of schistosomacide kinetic, observed every 24 h over a period of eight days. The results show that the worms were more sensitive to the PT5 derivative at a concentration of 58 microM which killed 100% of the worms after 24 h of contact, also giving rise to alterations in the tegument surface of the worms with the formation of bubbles and peeling. These observations suggest a strong electronic contribution of the arylazo grouping in the biological response.

Preliminary results on interleukin-4 and interleukin-10 cytokine production in malnourished, inducible nitric oxide synthase-deficient mice with schistosomiasis mansoni infection.

Schistosoma mansoni infected C57Bl/6 inducible nitric oxide synthase (iNOS)-deficient and non-deficient malnourished mice, both fed a balanced controlled diet were studied. Interleukins, IL-4 and IL-10 responses to soluble egg antigens (SEA) 90 days after infection, were determined. Our results suggest that in iNOS deficient, malnourished mice, 90 days after of infection, nitric oxide has a downregulating effect on IL-4 and IL-10 production. We are currently investigating the biological significance of these findings.

[Proteic profile and antigenic recognition of extracts from Wuchereria bancrofti L3 infective larvae]. / Perfil protéico e reconhecimento antigênico de extratos de larvas infectantes (L3) de Wuchereria bancrofti.

A study of protein characterization and recognition of the antigenic profile was accomplished in extracts of infective larvae (L3) from Wuchereria bancrofti. Two proteins of relative molecular weight of 49 and 55 kDa were recognized as antigenic in all extracts by the tested sera. The secretory/excretory antigen presented the largest number of recognized bands (105, 100, 76, 55, 49, 39 and 32 kDa) followed by the somatic antigen (100, 76, 55 and 49 kDa) when incubated with pools of sera from healthy individuals resident in endemic areas (normal endemics). Human sera and parasitized blood used to infect mosquitoes in order to obtain L3, were collected from microfilaraemic individuals living in a filariasis endemic area. From 792 persons screened with the thick smear technique, 87 (11%) were positive. No statistical significance was observed between genders. The group between 11 and 19 years of age presented higher percentage of infection (36.8%).

Perfil protéico e reconhecimento antigênico de extratos de larvas infectantes (L3) de Wuchereria bancrofti / Proteic profile and antigenic recognition of extracts from Wuchereria bancrofti L3 infective larvae

A caracterização protéica dos extratos de larvas infectantes (L3) de Wuchereria bancrofti foi realizada por eletroforese em gel de poliacrilamida, em presença de dodecil sulfato de sódio (SDS-PAGE) e o reconhecimento antigênico das proteínas por Western-blot. O maior número de bandas protéicas reconhecidas foi evidenciado nos extratos AgSE (105, 100, 76, 55, 49, 39 e 32 kDa) e AgS (100, 76, 55, e 49 kDa) na presença de soros de indivíduos endêmicos normais. As bandas de 49 e 55 kDa foram reconhecidas pelos soros dos microfilarêmicos, endêmicos normais (residentes de área endêmica livres de infecção filarial) e portadores da forma crônica da doença. As larvas infectantes foram obtidas pela dissecção de mosquitos Culex quinquefasciatus infectados com sangue microfilarêmico de voluntários portadores de microfilaremia, residentes do Município de Olinda-PE. Nos 792 indivíduos investigados pela técnica da gota espessa mensurada (60æl de sangue) 87 foram positivos (11 por cento). A diferenca da positividade entre homens e mulheres não foi significativa e a faixa etária de 11 a 19 anos foi a de maior prevalência.